import os
from pyspark.sql import SparkSession

spark = SparkSession.builder.appName("sg-jdbc-read").getOrCreate()
spark.sparkContext.setLogLevel("ERROR")

orders = spark.read.jdbc(
    url=os.environ["JDBC_URL"],
    table="(SELECT order_id, customer_id, total FROM public.orders) AS orders",
    properties={
        "user": os.environ["JDBC_USER"],
        "password": os.environ["JDBC_PASSWORD"],
        "driver": "org.postgresql.Driver",
    },
)

orders.printSchema()
print(f"rows={orders.count()}")
orders.orderBy("order_id").show(5, truncate=False)

spark.stop()